Add generic functions for getting typed variation parameter values

components/variations/variations_associated_data.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/variations/variations_associated_data.h"
 
 #include <map>
 #include <utility>
 #include <vector>
 
 #include "base/feature_list.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/field_trial_param_associator.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "components/variations/variations_http_header_provider.h"
 
 namespace variations {
 
 namespace {
 
 // The internal singleton accessor for the map, used to keep it thread-safe.
 class GroupMapAccessor {
  public:
@@ skipping 157 matching lines @@
   if (!base::FeatureList::IsEnabled(feature))
     return std::string();
 
   base::FieldTrial* trial = base::FeatureList::GetFieldTrial(feature);
   if (!trial)
     return std::string();
 
   return GetVariationParamValue(trial->trial_name(), param_name);
 }
 
+int GetVariationParamByFeatureAsInt(const base::Feature& feature,
+                                    const std::string& param_name,
+                                    int default_value) {
+  std::string value_as_string =
+      GetVariationParamValueByFeature(feature, param_name);
+  int value_as_int = 0;
+  if (!base::StringToInt(value_as_string, &value_as_int)) {
+    if (!value_as_string.empty()) {
+      LOG(WARNING) << "Failed to parse variation param " << param_name

[Alexei Svitkine (slow), 2016/12/08 21:08:33]

Please turn these into DLOG()'s.

LOG() lines are not advised because they produce useless console spam for end
users and bloat the binary.

[jkrcal, 2016/12/09 06:59:31]

Done.

+                   << " with string value " << value_as_string
+                   << " under feature " << feature.name
+                   << " into an int. Falling back to default value of "
+                   << default_value;
+    }
+    value_as_int = default_value;
+  }
+  return value_as_int;
+}
+
+double GetVariationParamByFeatureAsDouble(const base::Feature& feature,
+                                          const std::string& param_name,
+                                          double default_value) {
+  std::string value_as_string =
+      GetVariationParamValueByFeature(feature, param_name);
+  double value_as_double = 0;
+  if (!base::StringToDouble(value_as_string, &value_as_double)) {
+    if (!value_as_string.empty()) {
+      LOG(WARNING) << "Failed to parse variation param " << param_name
+                   << " with string value " << value_as_string
+                   << " under feature " << feature.name
+                   << " into a double. Falling back to default value of "
+                   << default_value;
+    }
+    value_as_double = default_value;
+  }
+  return value_as_double;
+}
+
+bool GetVariationParamByFeatureAsBool(const base::Feature& feature,
+                                      const std::string& param_name,
+                                      bool default_value) {
+  std::string value_as_string =
+      variations::GetVariationParamValueByFeature(feature, param_name);
+  if (value_as_string == "true") {

[Alexei Svitkine (slow), 2016/12/08 21:08:32]

Nit: No {}'s here and below.

[jkrcal, 2016/12/09 06:59:31]

Done.

+    return true;
+  }
+  if (value_as_string == "false") {
+    return false;
+  }
+
+  if (!value_as_string.empty()) {
+    LOG(WARNING) << "Failed to parse variation param " << param_name
+                 << " with string value " << value_as_string
+                 << " under feature " << feature.name
+                 << " into a bool. Falling back to default value of "
+                 << default_value;
+  }
+  return default_value;
+}
+
 // Functions below are exposed for testing explicitly behind this namespace.
 // They simply wrap existing functions in this file.
 namespace testing {
 
 void ClearAllVariationIDs() {
   GroupMapAccessor::GetInstance()->ClearAllMapsForTesting();
 }
 
 void ClearAllVariationParams() {
   base::FieldTrialParamAssociator::GetInstance()->ClearAllParamsForTesting();
 }
 
 }  // namespace testing
 
 }  // namespace variations